BISMARCK - More temporary oil workers are expected in Williston, Dickinson and Minot this summer to catch up on a backlog of wells that need hydraulic fracturing, North Dakota's top oil and gas regulator said Monday.

Lynn Helms, director of the Department of Mineral Resources, said drilling crews are outpacing well completion crews. At the end of May, an estimated 500 oil wells were waiting on fracking crews.North Dakota oil production rose 2.1 percent in May to set an all-time high of 810,129 barrels per day, according to preliminary numbers from the department."We finally broke through that 800,000 barrel-a-day barrier," Helms said.Production increases are expected to be more substantial this summer as oil service companies bring in additional workers and equipment to catch up on the backlog, Helms said. They'll likely put pressure on housing in the three hub cities in the Bakken where the companies have headquarters, he said.Companies are taking an average of 22 days to drill a new oil well, but the length of time to complete the well and bring it on production has increased to 92 days, Helms said.North Dakota had the wettest May on record, which prompted restrictions on some roads to last longer than usual, making it difficult to move heavy equipment, sand and water used for hydraulic fracturing, Helms said.Some companies are refocusing their workforce to add more well-completion personnel in North Dakota instead of drilling crews, Helms said.The percentage of North Dakota crude oil transported by rail fell from 75 percent to 69 percent in May, said Justin Kringstad, director of the North Dakota Pipeline Authority.The change resulted from a shift in market prices, which prompted more oil to be transported by pipeline, Kringstad said.North Dakota officials are monitoring the investigation of the train carrying Bakken crude that derailed in Quebec."Continued shipment by rail is critical to continued development and production growth of North Dakota," Helms said. "Without it, price differentials and lower prices would have a big negative impact on what's happening in the Bakken and Three Forks."The price of sweet crude was $97 per barrel on Monday, up from an average of $85 to $87 in previous months. Helms attributes the increase to unrest in Egypt.North Dakota natural gas production rose 4.5 percent in May to 899,977 thousand cubic feet per day, also an all-time high.The percent of natural gas flared in May remained at 29 percent. The all-time high was 36 percent in September 2011.- See more at: http://www.bemidjipioneer.com/content/more-oil-workers-expected-catch-nd-wells-summer#sthash.JZ2JX1Lm.dpuf